--- a/browser/components/customizableui/PanelMultiView.jsm
+++ b/browser/components/customizableui/PanelMultiView.jsm
@@ -4,16 +4,18 @@
 
 "use strict";
 
 this.EXPORTED_SYMBOLS = ["PanelMultiView"];
 
 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
+  "resource://gre/modules/AppConstants.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "CustomizableWidgets",
   "resource:///modules/CustomizableWidgets.jsm");
 
 /**
  * Simple implementation of the sliding window pattern; panels are added to a
  * linked list, in-order, and the currently shown panel is remembered using a
  * marker. The marker shifts as navigation between panels is continued, where
  * the panel at index 0 is always the starting point:
@@ -875,21 +877,34 @@ this.PanelMultiView = class {
 
         // When using block-in-box layout inside a scrollable frame, like in the
         // main menu contents scroller, if we allow the contents to scroll then
         // it will not cause its container to expand. Thus, we layout first
         // without any scrolling (using "display: flex;"), and only if the view
         // exceeds the available space we set the height explicitly and enable
         // scrolling.
         if (this._mainView.hasAttribute("blockinboxworkaround")) {
-          let mainViewHeight =
-              this._dwu.getBoundsWithoutFlushing(this._mainView).height;
-          if (mainViewHeight > maxHeight) {
-            this._mainView.style.height = maxHeight + "px";
-            this._mainView.setAttribute("exceeding", "true");
+          let blockInBoxWorkaround = () => {
+            let mainViewHeight =
+                this._dwu.getBoundsWithoutFlushing(this._mainView).height;
+            if (mainViewHeight > maxHeight) {
+              this._mainView.style.height = maxHeight + "px";
+              this._mainView.setAttribute("exceeding", "true");
+            }
+          };
+          // On Windows, we cannot measure the full height of the main view
+          // until it is visible. Unfortunately, this causes a visible jump when
+          // the view needs to scroll, but there is no easy way around this.
+          if (AppConstants.platform == "win") {
+            // We register a "once" listener so we don't need to store the value
+            // of maxHeight elsewhere on the object.
+            this._panel.addEventListener("popupshown", blockInBoxWorkaround,
+                                         { once: true });
+          } else {
+            blockInBoxWorkaround();
           }
         }
         break;
       case "popupshown":
         // Now that the main view is visible, we can check the height of the
         // description elements it contains.
         this.descriptionHeightWorkaround();
         break;